I give up with my FSC card but just bought fairy cheap M1015 and after few problems succesfully flashed it to IR mode.
My M1015 was delievered with old 2009 firmware which didn't work well with any mobo in Win7 x64, device was not working after driver installation.
I'm not an expert, rather enthusiast and if I'm correct it basically works like this.
IT- mode is useful when you don't need any Raid modes, card will work as pure SAS/SATA controller with pass-through mode for drives which is great if you have many drives to connect and still you will have an option to make a software raid under OS, hardware raid level is removed which sometimes help with drive communication.
IR - hardware raid level is active and pass-through mode also which is great btw.
P11 is just a newest firmware.
And here are my few conclusions:
Indeed if you got "Failed to initialize PAL" error then it's your mobo fault (some incompatibilities). Disabling other OROM's and devices in bios most likely will not help you, you need to try it in another mobo.
The strangest thing is that mainboards which works with this raid cards perfectly well (all with integrated GPU - AMD and Intel), like my ASRock Z68 Extreme4 Gen3, Supermicro X9SCL/X9SCM and some Intel Core mobo failed to flash a firmware.
But mobo which have a problem to run my FSC card and runs out of memory on boot start - GA-MA790FXT-UD5P (without integrated GPU) will allow you to flash this firmware without any problems.